the snail probably wont make it thru the first ammonia swing if so then not thru the nitrites, but who knows, crazier things have happened, corals even have been known to lay "dormant" so to speak on lr,
as for the bristles i wouldnt even worry about them unless you start seeing them, imo and most everyone elses the good will normally outweigh the bad, just make sure to look into your tank at various hours, (including when its dark, because there are things that wont come out during light hours ever), if you do spot anything and you cant id it, there is a special hitch hikers thread that you can utilize and we can all help you determine what it is and if its helpful, harmful, or neutral
